Anisotropic conductive particles for electric connection are used in electrode-connecting materials for liquid crystal display panels and in anisotropic conductive films in mounting LSI chips. Such anisotropic conductive films that are in use are produced, for example, by dispersing metal-plated particles in an insulating material and molding the dispersion into film-like forms. When such an anisotropic conductive film is inserted between electrodes and heated under pressure, the insulating material melts and the metal-plated particles serve as conductive particles and the electrodes are electrically connected to each other.
However, with the recent trend toward finer interelectrode pitches, it becomes necessary to increase the level of addition of conductive particles in the anisotropic conductive films for securing high levels of connection reliability. This results, however, in transverse conduction by neighboring particles, for instance, and such problems as short circuiting between neighboring electrodes arise. For alleviating such problems, Japanese Kokai Publication Sho-62-40183, for instance, describes a method which comprises coating metal-plated particles with a resin incompatible with the film layer resin and grinding the resulting mass to give particles, while Japanese Kokai Publication Hei-08-335407 describes a method which comprises coating metal-plated particles by microencapsulation. However, the methods mentioned above have drawbacks. Thus, the strength of bonding between the resin used for coating and the metal is weak, since the resin is only physically adsorbed on the metal-plated particles. In the step of grinding the aggregated particles into single and individual particles after coating treatment, the coating resin may be peeled off or the coating resin thickness may decrease, so that the metal-plated particle surface may be exposed, not only conduction in the electrode direction but also conduction in the transverse direction may occur, increasing short circuiting in the transverse direction. Another drawback of the above methods is that since a resin is layered on the metal particle surface, the laminate resin may be peeled off also in the step of kneading the coated particles with a binder resin or an adhesive. Furthermore, the resin may be peeled off from the coated particle surface even in the step of thermocompression bonding of the coated particle-containing anisotropic conductive film at elevated temperatures.